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Journal : IPTEK The Journal for Technology and Science

Maritime Weather Prediction using Fuzzy Logic in Ternate Waters North Maluku Sangadji, Anisa; Aisjah, Aulia Siti; Nugroho, Gunawan
IPTEK The Journal for Technology and Science Vol 27, No 2 (2016)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1011.444 KB) | DOI: 10.12962/j20882033.v27i2.1146

Abstract

Ternate waters of North Maluku is one of Indonesian eastern waters whose maritime weather is often unpredictable. Weathers prediction is important to avoid accidents in the waters. The aim of this research is to obtain              a predictor model of wave’s height and current’s speed suitable for the Ternate waters using Takagi-Sugeno fuzzy logic. The data used is data from BMKG Maritime of Bitung which recorded per 6 hours during 5 years from July 2010 – June 2015. In order to reach accuracy of > 85%, 3 model predictor’s that used waves height and current speed are predictor Model A, Model B and Model C. Each model uses different input and total membership function. The result of this research shows that the Model C is the best model for Ternate waters. Model C uses 4 membership functions for 3 input variables. Inputs of waves height predictor consist of the actual wind speed (U(t)), actual waves height (H(t)) and waves height 6 hours ago (H(t-6)) and accuracy percentage of waves height 6 hours ahead (H(t+6)) is 91,99%; while inputs of current speed predictor consist of actual wind speed (U(t)), actual current speed (Cu(t)) and current speed 6 hours ago (Cu(t-6)) and accuracy percentage of current speed 6 hours ahead (Cu(t+6)) is 81,63%.
Analysis of MARIA Reactor Safety Based on Efficiency Measurement of Shim Rod Using Method of Fixed Period Rachmatulloh, Hafizh Fatah; Pytel, Krzysztof; Siti Aisjah, Aulia
IPTEK The Journal for Technology and Science Vol 28, No 1 (2017)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (874.417 KB) | DOI: 10.12962/j20882033.v28i1.1320

Abstract

An experiment was conducted in MARIA reactor as the part of reactivity measurement inside the reactor using method of fixed period while MARIA reactor was being started up. It was important as performance indicator that shim rod worked well and able to maintain reactivity on the level not exceeding the value of 1$ by compensating the excess reactivity to provide reactor safety. The measurement was done directly at MARIA reactor control room on April 28th, 2015 using digital reactimeter, therefore, it allowed performing continuous measurement of reactor reactivity. Data at shim rod – 5 (PK-5) was collected, with time interval 0.49 S. Preliminary calculations were done by neglecting the presence of photoneutrons. For the result, at full shim rod insertion (1067 mm) absorbed reactivity with value 0,92$ was obtained. The result showed that the shim rod worked well because the reactivity never exceeding 1$. The result as an early parameter that guarantees MARIA reactor safety from burning out the claddings of fuel elements and radiological accident.